Cryogenic Invar®, notably Invar® M93, are alloys which have low thermal expansion coefficients, which makes them notably attractive for transporting cryogenic fluids.
In such applications, elements made of cryogenic Invar® of different thicknesses may be assembled, for example by welding.
The thereby obtained assemblies do not give entire satisfaction. Indeed, the welds form weakened areas of the structures formed by the assembled elements. The presence of these weakened areas may result in a reduction of the fatigue strength.